Stroke-increasing device



` Filed Oct. 14. 1938. 2 Sheets-Sheet l .7367?? Few/fw,

91mg. s, 1939. P, REPKA 9 2,169,126

STROKE-INCREASING DEVICE Filed Oct4 14, 1938 2 Sheets-Sheet 2 Patented Aug. 8, 1939 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to a new and useful device ior increasing the stroke of pump piston rods and the like which are actuated by a second power driven reciprocating rod.

The primary object of the present invention is to provide a device of the above kind which will be smooth and efficient in operation and which will require the expenditure of a minimum amount of power for actuating the pump or other driven reciprocating rod.

A further object of the present invention is to provide a device of the above kind which permits operative connection of the driven and driving rod in axial alinement so as to afford a compact con- 15,Y struction of maximum operating eiliciency.

A still further object is to provide a stroke-increasing device of the character set forth above which is extremely simple in construction, easy and economical to manufacture and install, and

otherwise adapted for successful commercial use.

The present invention consists in the novel form, combination and arrangement of parts hereinafter more fully described, shown in the accompanying drawings, and claimed.

In the drawings:

Figure 1 is afragmentary side elevational view, partly broken away, of a wind-mill derrick and pump with the pump rod operatively connected to the actuating rod thereof by means of a strokeincreasing device constructed in accordance with the present invention.

Figure 2 is an enlarged horizontal section on line 2--2 of Figure 1.

Figure 3 is an enlarged fragmentary vertical section illustrating more clearly the detailed construction of the stroke-increasing device shown in Figure 1; and

Figure 4 is a fragmentary vertical section on line 4 4 of Figure 3.

While the present invention is applicable to many different kinds of apparatus or machines wherein a reciprocating rod is to be driven by a second reciprocating actuating rod so as to have a longer stroke than the latter, the invention has been shown and will be described in connection with the actuation of a pump piston rod associated with well derricks. In the drawings, the derrick structure is broadly designated at 5, and centrally arranged within this derrick structure is the piston rod 6 extending upwardly from a pump, not shown. In order to reciprocate the pump piston rod 6 by means of a second actuating rod 1 disposed above and axially alined therewith, so that said pump piston rod 6 will have a greater length of stroke than the actuating rod "I, I provide the novel stroke-increasing device now to be described. This device consists of a pair of links 8 pivotally connected at their lower ends to the upper end of the pump piston rod 6 as generally indicated at 9. Thelinks 8 extend 5 upwardly in diverging relation and are pivotally connected at their upper ends to the inner end of levers I!) pivotally mounted within the derrick structure intermediate their ends as at II. In order to pivotally support the levers I0, their l0 pivots are carried by a pair of horizontal supporting bars I2 rigidly fastened to and extending diagonally across the derrick structure 5 from one corner thereof to the opposed corner as clearly shown in Figure 2, the pivots I I extending through vertical flanges of the bars I2 and the levers I0 being mounted on said pivots between the bars I2 as also clearly shown in Figure 2. Attached to the lower end of the actuating rod 'I is a cross bar I3 the ends of which are operatively connected with the levers I0 by means of depending downwardly diverging links I4 whose upper ends are pivoted to the cross bar I3 and whose lower ends are pivotally connected to the levers I0 at points intermediate the pivots II and the inner ends of said levers which are connected to the links 8. It is thus apparent that upon reciprocation of rod l, such reciprocation will be imparted to pump piston rod 6, but the latter will be given a stroke considerably longer than that of the actuating rod 1. The increase of stroke may be determined by the distance at which the lower ends of links I4 are connected with the levers IE! from the pivots II of the latter.

It will be noted that the present device provides for arrangement of the rods 6 and 1 in axial alinement so that a durable compact arrangement is had which will be very eflicient in operation. In order to minimize the amount of power required for actuation of the rod 6, the weight of said rod 6, links 8 and levers I0 may be counterbalanced by means of helical tension springs I5 connected at their upper ends to the outer ends of inclined levers I0 and adjustably connected at their lower ends to the lower ends of bracket I6 attached to the derrick structure at oposite sides of the levers IU and depending below the latter as clearly shown in Figures 1 and 3. The adjustable connection of springs I5 with brackets IB permits adjusting the tension of said springs so that their counterbalancing action may be maintained at maximum efficiency at all times even though such springs should gradually weaken from continued use. 'I'he actuation rod 'I has a depending extension I'I at its lower end which slidably extends through a guide I8 mounted on the supporting bars I2, so as to restrain the actuating rod 'I against lateral movement and thereby assist in insuring smooth eicient operation. In use, the rod I is moved downwardly so as to cause corresponding movement of links I4 and thereby cause the inner end portions of levers IU to swing downwardly. The latter causes downward movement of links 8 and rod 6 for a considerably greater' distance than the length of movement of rod "I and links I4, thereby insuring a relatively increased stroke for the actuated rod 6. When the rod 'I reaches its downward limit of movement, it moves upwardly and a reversal of the above operation takes place, the rod 6 moving upwardly a greater distance than the rod 1. Usually, the .actuating rod 'I is operated by a wind wheel at the top of the derrick structure, the shaft of said wind wheel having a crank operatively connected to the upper end of rod 7. The size of this crank need not be increased in order to effect an increase in the length of the stroke of rod 6, when the present invention is employed tween the rods 6 and 'l as illustrated and described. The distance at which the lower ends of links I4 are connected to the levers I0 from their pivots II may be varied any suitable way, such as provision of a longitudinal series of openings I9 in the inner arms of levers Ill adapted for selective reception of the pivot pins 20 which connect said links I4 with said lever I0, as shown in Figure 3.

From the foregoing description, it is believed that the construction and operation, as well as the advantages of the present invention will be readily understood and appreciated by those skilled in the art. It will be apparent that the invention is susceptible of various changes and embodiments, the specific details of construction and the particular embodiment shown and described being merely chosen by way of example.

What I claim as new is:

l. In combination, a rod to be reciprocated, a second power driven reciprocating rod alined with said first-named rod, means operatively connecting the adjacent ends of said rods whereby the first-named rod is given a stroke of greater length than the stroke of said second-named rod, said last-named means comprising a fixed support, levers arranged at opposite sides of said rods and pivoted intermediate their ends to said support normally in downwardly diverging relation, a cross bar secured on the lower end portion of the second-named rod, links pivoted to the ends of said cross bar at their upper ends and to the inner arms of said levers at their lower ends, and further links pivotally connecting the inner ends of said levers with the upper end of the rst-named rod.

2. In combination, a rod to be reciprocated, a second power driven reciprocating rod alined with said rst-named rod, means operatively connecting the adjacent ends of said rods whereby the first-named rod is given a stroke of greater length than the stroke of said secondnamed rod, said last-named means comprising a fixed support, levers arranged at opposite sides of said rods and pivoted intermediate their ends to said support normally in downwardly diverging relation, a cross bar secured on the lower end portion of the second-named rod, links pivoted to the ends of said cross bar at their upper ends and to the inner arms of said levers at their lower ends, further links pivotally connecting the inner ends of said levers with the upper end of the first-named rod, and means connected to the outer arms of said levers for counterbalancing the latter, the second-named links and the first-named rod.

3. A structure as set forth in claim 2, wherein said counterbalancing means comprises brackets attached to and depending from said support, and helical tension springs connected at their upper ends to the outer .arms of said levers and adjustably connected at their lower ends to said brackets so that the tension of said springs may be adjusted.

4. In combination, a derrick structure, a pump piston rod to be reciprocated, a second powerdriven reciprocating rod .alined with said rstnamed rod, and means operatively connecting the adjacent ends of said rods whereby the rstnamed rod is given a stroke of greater length than the stroke of said second-named rod, said last-named means comprising a fixed support mounted horizontally between opposed corners of said derrick structure and comprising spaced bars, levers arranged at opposite sides of said rods and pivoted intermediate their ends to and between the bars of said support normally in downwardly diverging relation, a cross bar secured on the lower end portion of the secondnamed rod, links pivoted to the ends of said cross bar at their upper ends and to the inner arms of said levers at their lower ends, further links pivotally connecting the inner ends of said levers with the upper end of the first-named rod, a guide mounted on said bars, and a depending extension. on the lower end of said second-named rod slidably engaged in said guide.

PETER REPKA. 

